Тёмный

Syntax directed definition(SDD) in compier design||Types of attributes||Types of SDD 

Sudhakar Atchala
Подписаться 180 тыс.
Просмотров 294 тыс.
50% 1

#syntaxdirecteddefinition #compilerdesigntutorial #typesofattributes
syntax directed definition in compiler design
Compiler Design | Syntax Directed Definition
Syntax Directed Definition (SDD) and Types of Syntax Directed Definitions
Attribute grammar
S - attributed and L - attributed SDTs in Syntax directed translation

Опубликовано:

 

27 сен 2024

Поделиться:

Ссылка:

Скачать:

Готовим ссылку...

Добавить в:

Мой плейлист
Посмотреть позже
Комментарии : 174   
@koslipraneeth5648
@koslipraneeth5648 2 года назад
Sir I'm having CD exam tomorrow and this is my last attempt if I clear this I'll remember you for rest of my life sir and thank you for helping me sir💕💕
@SudhakarAtchala
@SudhakarAtchala 2 года назад
All the best. Plz subscribe to the channel and if possible share with your friends. Thanks in advance.
@jayeshmishra7
@jayeshmishra7 4 года назад
Hi sir, just wanted to thank you for doing this and helping out many other students like me :) I scored AA in CD all because of your videos. Thanks alot sir.
@SudhakarAtchala
@SudhakarAtchala 4 года назад
Congratulations
@aryanakshay8499
@aryanakshay8499 3 года назад
I was Reading the lecture notes from morning and i was unable to understand much. But your videos helped me a lot to understand these concepts very easily. Thankyou sir.
@SudhakarAtchala
@SudhakarAtchala 3 года назад
Please Subscribe to the channel and if possible share with your friends. Thanks
@vishnupemmasani6144
@vishnupemmasani6144 4 года назад
Superrr teaching you helped me getting 12 marks in my today's sem thanks for your great explanation
@SudhakarAtchala
@SudhakarAtchala 4 года назад
Keep it up
@kresh1619
@kresh1619 2 года назад
crystal clear and patient explanation . Thought that SDD was complex till I watched your tutorial . Thank you , sir.
@SudhakarAtchala
@SudhakarAtchala 2 года назад
Welcome. Plz subscribe to the channel and if possible share with your friends. Thanks in advance.
@smatilboddu8802
@smatilboddu8802 3 года назад
Literally..now I got hope that I will pass in xam..thank you sir..❤️ You are explanation is just awesome. Sir🙏
@SudhakarAtchala
@SudhakarAtchala 3 года назад
All the best. Plz subscribe to the channel and if possible share with your friends. Thanks
@user-wf7oq3iz5j
@user-wf7oq3iz5j 2 года назад
You are the best I finally understand Syntax-Directed Definition I shared your video with all my friends thank you sir
@SudhakarAtchala
@SudhakarAtchala 2 года назад
Welcome.
@sonurj4287
@sonurj4287 4 года назад
Sir, thank you for last moment concepts for exams. Very Simple yet elegantly explained.
@SudhakarAtchala
@SudhakarAtchala 4 года назад
Hai Sonu Rj, plz go through my playlists once. Definitely you will like more videos. Thanks for your encouragement and support towards our channel.Share my sessions with your friends and subscribe to our channel.Keep on following my sessions. Thank you so much.
@sonurj4287
@sonurj4287 4 года назад
Sure, Sir i will. I would love to see more videos. If 8th semester CSE subjects videos are coming So, I am more excited for that.
@ahmakhan8442
@ahmakhan8442 3 года назад
Very lucid and nice Explanation. SIR
@SudhakarAtchala
@SudhakarAtchala 3 года назад
Thanks and welcome ahma. Plz subscribe to the channel and if possible share with your friends. Thanks in advance.
@aryansingh-se7jv
@aryansingh-se7jv Год назад
crystal clear explanation wonderful teaching sir
@SudhakarAtchala
@SudhakarAtchala Год назад
Thanks and welcome. Plz subscribe to the channel and if possible share with your friends. Thanks in advance..
@dasarivinaykumar9238
@dasarivinaykumar9238 3 года назад
Sir I think your a blessed person. When I am listening your videos I have a good feeling in my heart.
@SudhakarAtchala
@SudhakarAtchala 3 года назад
Wow, thank you Vinay. Plz subscribe to the channel and if possible share with your friends. Thanks in advance.
@vusakoilas6185
@vusakoilas6185 3 года назад
Thank you so much sir. The content is clear😊
@SudhakarAtchala
@SudhakarAtchala 3 года назад
Most welcome 😊. Plz subscribe to the channel and if possible share with your friends. Thanks
@gamerbros8014
@gamerbros8014 4 месяца назад
Really beautiful teaching sir,liked and shared
@SudhakarAtchala
@SudhakarAtchala 4 месяца назад
Thanks.
@Roshini_Shaik08
@Roshini_Shaik08 3 месяца назад
Good explanation sir.... Tomorrow i have exam.... You saved me....☺️
@SudhakarAtchala
@SudhakarAtchala 3 месяца назад
All the best. Plz subscribe to the channel and if possible share with your friends. Thanks in advance.
@Krishna-z1g5r
@Krishna-z1g5r 6 месяцев назад
Thank you so much sir your videos are helping me a lot.. please more videos
@SudhakarAtchala
@SudhakarAtchala 6 месяцев назад
Sure I will. Plz subscribe to the channel and if possible share with your friends. Thanks in advance..
@ashen_vortex
@ashen_vortex 5 лет назад
Great explanation. Much help.
@SudhakarAtchala
@SudhakarAtchala 5 лет назад
Hai Arun Ajgale Thanks for your encouragement and support towards our channel.Share my sessions with your friends and subscribe to our channel.Keep on following my sessions. Thank you so much.
@sunitsable2752
@sunitsable2752 10 месяцев назад
amazing explaination sir !!
@SudhakarAtchala
@SudhakarAtchala 10 месяцев назад
Thanks and welcome. Plz subscribe to the channel and if possible share with your friends. Thanks in advance..
@dipkumardas3941
@dipkumardas3941 11 месяцев назад
Hi Sir Thank you for the amazing playlist
@SudhakarAtchala
@SudhakarAtchala 11 месяцев назад
You are very welcome. Plz subscribe to the channel and if possible share with your friends. Thanks in advance..
@samudralashanmukrao2185
@samudralashanmukrao2185 2 года назад
Sir please do video on implementing L attributed sdds concept i am very struggling to understand that concept..plz do video as early as possible
@krishnavenivangala6728
@krishnavenivangala6728 2 года назад
Superb explanation
@SudhakarAtchala
@SudhakarAtchala 2 года назад
Thanks. Plz subscribe to the channel and if possible share with your friends. Thanks in advance.
@hannanansari9288
@hannanansari9288 2 года назад
Superb explanation sir! thank you so much!
@SudhakarAtchala
@SudhakarAtchala 2 года назад
Welcome. Plz subscribe to the channel and if possible share with your friends. Thanks in advance.
@_glock_69_
@_glock_69_ Год назад
What is different between sdd and sdt
@smile-tk7yt
@smile-tk7yt 3 года назад
Thanks a lot sir🙏🙏. Stay blessed.
@SudhakarAtchala
@SudhakarAtchala 3 года назад
Most welcome. Plz subscribe to the channel and if possible share with your friends. Thanks in advance.
@realhomegadgets7104
@realhomegadgets7104 3 года назад
nice Explaination Guruji
@SudhakarAtchala
@SudhakarAtchala 3 года назад
Thanks Sohail. Plz subscribe to the channel and if possible share with your friends. Thanks
@realhomegadgets7104
@realhomegadgets7104 3 года назад
Sure Sir
@DuoVegaVias
@DuoVegaVias 3 года назад
Thanks a Lot.. sir.. Easily explained every concept.. We are expecting more from U sir... 💚💚
@SudhakarAtchala
@SudhakarAtchala 3 года назад
Sure 👍 Navin. Plz subscribe to the channel and if possible share with your friends. Thanks in advance.
@Hello1239-e
@Hello1239-e Месяц назад
సాక్షాత్తు సరస్వతి పుత్రడు His immense knowledge in every tough subject is incredible,and having ability to explain in such easy manner for student Is very rare talent I'm following from past 4 years now i'm in final year of BTech I will Miss you sir I can't imagine the amount of pressure I used to handle in exam time ,but His vedios give confidence and subject knowledge so that I can crack exam There are many youtubers but I'm lucky to born in Sudhakar sir's era🔥
@SudhakarAtchala
@SudhakarAtchala 28 дней назад
Many Many Thanks for your kind words.
@angrynanda8022
@angrynanda8022 9 месяцев назад
Thank you 😊
@SudhakarAtchala
@SudhakarAtchala 9 месяцев назад
You're welcome 😊. Plz subscribe to the channel and if possible share with your friends. Thanks in advance..
@sivaupputuri7495
@sivaupputuri7495 Год назад
Your teaching very nice sir, l want oor subject class vedioe sir
@SudhakarAtchala
@SudhakarAtchala Год назад
Will upload soon. Plz subscribe to the channel and if possible share with your friends. Thanks in advance..
@anunudurumati2055
@anunudurumati2055 3 года назад
Thank you so much sirr ...Really helpful
@SudhakarAtchala
@SudhakarAtchala 3 года назад
Most welcome anu. Plz subscribe to the channel and if possible share with your friends. Thanks in advance.
@kprasanthkumar1815
@kprasanthkumar1815 2 года назад
Good Explanation sir 👍
@SudhakarAtchala
@SudhakarAtchala 2 года назад
Thanks. Plz subscribe to the channel and if possible share with your friends. Thanks in advance.
@anshul0961
@anshul0961 8 месяцев назад
The power of knowledge can only be understand a night before the exam.
@SudhakarAtchala
@SudhakarAtchala 8 месяцев назад
All the best. Plz subscribe to the channel and if possible share with your friends. Thanks in advance..
@rajshah6026
@rajshah6026 3 года назад
amazing explanation sir!!!
@SudhakarAtchala
@SudhakarAtchala 3 года назад
Thanks and welcome. Plz subscribe to the channel and if possible share with your friends. Thanks
@Vivek-hg4mm
@Vivek-hg4mm 2 года назад
Thaaannnkkkkyyyyyyyyyyyooooouuu. Saaaar 😘 तूमारू is my xaaaam
@SudhakarAtchala
@SudhakarAtchala 2 года назад
All the best. Plz subscribe to the channel and if possible share with your friends. Thanks in advance.
@24_bhagyashreekanamadi70
@24_bhagyashreekanamadi70 2 года назад
best teacher
@SudhakarAtchala
@SudhakarAtchala 2 года назад
Thanks. Plz subscribe to the channel and if possible share with your friends. Thanks in advance.
@vidhyan1254
@vidhyan1254 4 года назад
Tq sir good explanation
@SudhakarAtchala
@SudhakarAtchala 4 года назад
Plz subscribe to our channel and if possible share with your friends. Thanks
@dyagalavaishnavi5472
@dyagalavaishnavi5472 3 года назад
Thank you soo much sir.
@SudhakarAtchala
@SudhakarAtchala 3 года назад
Welcome. Plz subscribe to the channel and if possible share with your friends. Thanks in advance.
@manojvemisetti4060
@manojvemisetti4060 3 года назад
sir your lectures are soo good and easy to understand but i strucked at one point. can you give some example for 2nd point in s-attributed SDD @ 12:37
@theshahzorahmed6967
@theshahzorahmed6967 7 месяцев назад
thank you so much sir
@SudhakarAtchala
@SudhakarAtchala 7 месяцев назад
Most welcome. Plz subscribe to the channel and if possible share with your friends. Thanks in advance...
@VoiceThatMatter
@VoiceThatMatter Год назад
Thank you Sir.
@SudhakarAtchala
@SudhakarAtchala Год назад
Welcome. Plz subscribe to the channel and if possible share with your friends. Thanks in advance.
@safeerhussain7371
@safeerhussain7371 9 месяцев назад
very good.
@SudhakarAtchala
@SudhakarAtchala 9 месяцев назад
Many many thanks. Plz subscribe to the channel and if possible share with your friends. Thanks in advance..
@sheebageorge4804
@sheebageorge4804 4 года назад
Thanku Sir
@Manish-xc6is
@Manish-xc6is 3 года назад
Meeru devudu sir
@SudhakarAtchala
@SudhakarAtchala 3 года назад
Plz subscribe to the channel and if possible share with your friends. Thanks in advance.
@Manish-xc6is
@Manish-xc6is 3 года назад
@@SudhakarAtchala done sir I will share it to my friend Living legend rajesh
@gauravbhandari1184
@gauravbhandari1184 4 года назад
Helpful
@SudhakarAtchala
@SudhakarAtchala 4 года назад
Hai Gaurav Bhandari, plz go through my playlists once. Definitely you will like more videos. Thanks for your encouragement and support towards our channel.Share my sessions with your friends and subscribe to our channel.Keep on following my sessions. Thank you so much.
@sumanroy9479
@sumanroy9479 4 года назад
Thanks sir
@SudhakarAtchala
@SudhakarAtchala 4 года назад
Hai Suman, plz go through my videos once. Definitely you will like more videos. Thanks for your encouragement and support towards our channel. Share my sessions with your friends and subscribe to our channel.Keep on following my sessions. Thank you so much.
@someshmahajan7903
@someshmahajan7903 5 лет назад
Thank you so much
@SudhakarAtchala
@SudhakarAtchala 5 лет назад
Hai Somesh Mahajan Thanks for your encouragement and support towards our channel.Share my sessions with your friends and subscribe to our channel.Keep on following my sessions. Thank you so much.
@vinayreddy6632
@vinayreddy6632 Год назад
👍
@SudhakarAtchala
@SudhakarAtchala Год назад
Thanks. Plz subscribe to the channel and if possible share with your friends. Thanks in advance..
@askhere373
@askhere373 3 года назад
🔥
@SudhakarAtchala
@SudhakarAtchala 3 года назад
Thanks
@maruboyinasriramya7084
@maruboyinasriramya7084 4 года назад
Could you please provide any material for cd because I have to prepare for exam
@SudhakarAtchala
@SudhakarAtchala 4 года назад
Sorry to say this, I dont have any material as i prepared in some rough note books.
@SudhakarAtchala
@SudhakarAtchala 4 года назад
Hai SriRamya, plz go through my videos once. Definitely you will like more videos. Thanks for your encouragement and support towards our channel. Share my sessions with your friends and subscribe to our channel.Keep on following my sessions. Thank you so much.
@dr.dheerajtandon
@dr.dheerajtandon 4 года назад
Nice class#DheerajTandon
@SudhakarAtchala
@SudhakarAtchala 4 года назад
Hai Dheeraj ji, plz go through my videos once. Definitely you will like more videos. Thanks for your encouragement and support towards our channel. Share my sessions with your friends and subscribe to our channel.Keep on following my sessions. Thank you so much.
@nquanta1548
@nquanta1548 Год назад
Thankyou for the video sir 🎉🔥
@SudhakarAtchala
@SudhakarAtchala Год назад
Most welcome. Plz subscribe to the channel and if possible share with your friends. Thanks in advance..
@tejateju6137
@tejateju6137 3 года назад
Tq sir
@SudhakarAtchala
@SudhakarAtchala 3 года назад
welcome. Plz subscribe to the channel and if possible share with your friends. Thanks in advance.
@Saikiran-ek2hb
@Saikiran-ek2hb 2 года назад
are you from south india ?
@SudhakarAtchala
@SudhakarAtchala 2 года назад
Yes . Plz subscribe to the channel and if possible share with your friends. Thanks in advance.
@jaskiratsingh777
@jaskiratsingh777 5 лет назад
sir i have my exam tomorrow and i desperarelt want to learn STD
@jaskiratsingh777
@jaskiratsingh777 5 лет назад
so i am watching yr videos ,and its looks absolutely fantastic,thanks sir
@SudhakarAtchala
@SudhakarAtchala 5 лет назад
K. Plz subscribe to the channel and share with your friends thank you so much.
@mistrspunky8691
@mistrspunky8691 27 дней назад
Still watching your in 2024
@SudhakarAtchala
@SudhakarAtchala 26 дней назад
Thanks. Please like the videos, subscribe to the channel, and share it with your friends. Thanks in advance.
@nidhigupta7576
@nidhigupta7576 4 года назад
Sir what is difference between SDD,SDT
@SudhakarAtchala
@SudhakarAtchala 4 года назад
In sdt we can place semantic action any where in rhs by enclosing in curley braces. Where as in sdd no curley braces needed and it shouldn't be placed any where in rhs
@SudhakarAtchala
@SudhakarAtchala 4 года назад
Hai Nidhi, plz go through my videos once. Definitely you will like more videos. Thanks for your encouragement and support towards our channel. Share my sessions with your friends and subscribe to our channel.Keep on following my sessions. Thank you so much.
@nidhigupta7576
@nidhigupta7576 4 года назад
Thank you sir for your reply
@pushpalavanisree8729
@pushpalavanisree8729 4 года назад
Thank you so much sir,we need no other reference material if we watch u r video.😌😌
@SudhakarAtchala
@SudhakarAtchala 4 года назад
Hai Pushpala Vanisree, plz go through my playlists once. Definitely you will like more videos. Thanks for your encouragement and support towards our channel.Share my sessions with your friends and subscribe to our channel.Keep on following my sessions. Thank you so much.
@alekhyachawla1326
@alekhyachawla1326 3 года назад
Thank you sir🙏
@SudhakarAtchala
@SudhakarAtchala 3 года назад
Welcome. Plz subscribe to the channel and if possible share with your friends. Thanks in advance.
@alekhyachawla1326
@alekhyachawla1326 3 года назад
Sure sir 😊
@sufiyanahmad3854
@sufiyanahmad3854 10 месяцев назад
Thanks sir
@SudhakarAtchala
@SudhakarAtchala 10 месяцев назад
So nice of you. Plz subscribe to the channel and if possible share with your friends. Thanks in advance..
@sufiyanahmad3854
@sufiyanahmad3854 10 месяцев назад
@@SudhakarAtchala done sir
@rithikalincy3611
@rithikalincy3611 Год назад
👍
@SudhakarAtchala
@SudhakarAtchala Год назад
Thanks. Plz subscribe to the channel and if possible share with your friends. Thanks in advance.
@Jaydonj
@Jaydonj 6 месяцев назад
Sir, Does S attribute and L attribute come under SDD or SDT?
@SudhakarAtchala
@SudhakarAtchala 6 месяцев назад
Both. Plz subscribe to the channel and if possible share with your friends. Thanks in advance..
@Jaydonj
@Jaydonj 6 месяцев назад
@@SudhakarAtchala sure sir!!🫡🫡
@CrazyCrates
@CrazyCrates Месяц назад
30min before exam
@SudhakarAtchala
@SudhakarAtchala Месяц назад
All the best. Please like the video, subscribe to the channel, and share it with your friends. Thanks in advance.
@ramakrishnasanda2154
@ramakrishnasanda2154 Месяц назад
Great.... No reply???
@SudhakarAtchala
@SudhakarAtchala Месяц назад
All the best. Please like the video, subscribe to the channel, and share it with your friends. Thanks in advance.
@somithan8012
@somithan8012 2 года назад
Your vedio is helping out many students.. You made me to understand this concept within 15 min... Thank you sir
@SudhakarAtchala
@SudhakarAtchala 2 года назад
Welcome. Plz subscribe to the channel and if possible share with your friends. Thanks in advance.
@mannpreeth4537
@mannpreeth4537 4 месяца назад
My man you are genius
@SudhakarAtchala
@SudhakarAtchala 4 месяца назад
Thanks. Plz subscribe to the channel and if possible share with your friends. Thanks in advance..
@sanarafiqsa
@sanarafiqsa 3 года назад
just last moment preparation N results are awesomeee.........sir best ever teaching method
@SudhakarAtchala
@SudhakarAtchala 3 года назад
All the best sanarafiq. Plz subscribe to the channel and if possible share with your friends. Thanks in advance.
@akshaysuresh8654
@akshaysuresh8654 5 лет назад
Good explanation Sir.. God bless you!!
@SudhakarAtchala
@SudhakarAtchala 5 лет назад
Plz subscribe to the channel and share with your friends thank you so much.
@sowjanyareddy4632
@sowjanyareddy4632 6 месяцев назад
Thank you so much sir 😊 nice explanation
@SudhakarAtchala
@SudhakarAtchala 6 месяцев назад
Most welcome. Plz subscribe to the channel and if possible share with your friends. Thanks in advance..
@akshaysuresh8654
@akshaysuresh8654 5 лет назад
Good explanation Sir.. God bless you!!
@SudhakarAtchala
@SudhakarAtchala 5 лет назад
Plz subscribe to the channel and share with your friends thank you so much.
@tanvikalaskar6682
@tanvikalaskar6682 4 месяца назад
Survived btech life because of you 🙏👍 Thankyou so much
@SudhakarAtchala
@SudhakarAtchala 4 месяца назад
Most welcome. Plz subscribe to the channel and if possible share with your friends. Thanks in advance..
@zaibafathima8101
@zaibafathima8101 3 года назад
I Love your teaching ..Your teaching very Right way Sir❤️❤️ All other some youtube channels r Just 😑...Thankyou Sir ..Don't Worry Soon You wil See Many subscribers 🙏🙏
@SudhakarAtchala
@SudhakarAtchala 3 года назад
So nice of you
@IshaanSammeta
@IshaanSammeta Год назад
Sir please update playlist with new syllabus drive.google.com/file/d/1BZhCa3EUfPrGzr8kxgUSO_8wbUPYsxkc/view
@SudhakarAtchala
@SudhakarAtchala Год назад
Which subject cd or some other.Plz subscribe to the channel and if possible share with your friends. Thanks in advance..
@IshaanSammeta
@IshaanSammeta Год назад
@@SudhakarAtchala CD only sir
@ajinnandu
@ajinnandu 2 года назад
Thanku so much sir... Because of you exam was very easy😍😍😍🥰
@SudhakarAtchala
@SudhakarAtchala 2 года назад
Thanks. Plz subscribe to the channel and if possible share with your friends. Thanks in advance.
@sifou7974
@sifou7974 2 года назад
your explination is the best thanks
@SudhakarAtchala
@SudhakarAtchala 2 года назад
You are welcome! Plz subscribe to the channel and if possible share with your friends. Thanks in advance.
@pavan5364
@pavan5364 2 года назад
Thank you 🙂 nice explanation .
@SudhakarAtchala
@SudhakarAtchala 2 года назад
Welcome. Plz subscribe to the channel and if possible share with your friends. Thanks in advance.
@prahaladmugi9275
@prahaladmugi9275 9 месяцев назад
Nice explaination sir
@SudhakarAtchala
@SudhakarAtchala 9 месяцев назад
Thanks and welcome. Plz subscribe to the channel and if possible share with your friends. Thanks in advance..
@pawanchawan5643
@pawanchawan5643 5 лет назад
Very helpful thank you sir🙂🙂
@SudhakarAtchala
@SudhakarAtchala 5 лет назад
Hai Pawan chawan Thanks for your encouragement and support towards our channel.Share my sessions with your friends and subscribe to our channel.Keep on following my sessions. Thank you so much.
@BABLUKUMARBAMBAL
@BABLUKUMARBAMBAL 3 года назад
Amazing sir
@SudhakarAtchala
@SudhakarAtchala 3 года назад
Many many thanks. Plz subscribe to the channel and if possible share with your friends. Thanks
@saivenkatmaheshwaram9868
@saivenkatmaheshwaram9868 3 года назад
super explanation sir.
@SudhakarAtchala
@SudhakarAtchala 3 года назад
Thanks and welcome. Plz subscribe to the channel and if possible share with your friends. Thanks
@human-011
@human-011 3 года назад
awesome
@SudhakarAtchala
@SudhakarAtchala 3 года назад
Glad it helped Raman. Plz subscribe to the channel and if possible share with your friends. Thank you so much.
@10k.harshavardhanreddy67
@10k.harshavardhanreddy67 Год назад
Thanku sir
@SudhakarAtchala
@SudhakarAtchala Год назад
Most welcome. Plz subscribe to the channel and if possible share with your friends. Thanks in advance..
@bhavanigollapelly
@bhavanigollapelly 3 года назад
Tq sir...
@SudhakarAtchala
@SudhakarAtchala 3 года назад
Plz subscribe to the channel and if possible share with your friends. Thanks
@musablatifi8610
@musablatifi8610 Год назад
👍
@SudhakarAtchala
@SudhakarAtchala Год назад
Thanks. Plz subscribe to the channel and if possible share with your friends. Thanks in advance..
@kowsalya_s0183
@kowsalya_s0183 3 года назад
Excellent explanation
@SudhakarAtchala
@SudhakarAtchala 3 года назад
Glad it was helpful Kowsalya. Plz subscribe to the channel and if possible share with your friends. Thanks in advance.
@kowsalya_s0183
@kowsalya_s0183 3 года назад
@@SudhakarAtchala ok sir